Question

Effect of initial periodontal therapy on gingival crevicular fluid cytokine profile in subjects with chronic periodontitis

Answer 1

Cytokines are thought to play an important role in the pathogenesis of periodontal disease. Because periodontal disease is known for its inhomogeneous distribution within the dentition, it is unclear to what extent the detection of various cytokines at different sites correlates with presence of disease. We evaluated whether levels of 12 cytokines in gingival crevicular fluid (GCF) discriminated periodontally diseased sites from healthy ones, or periodontally diseased persons from healthy ones, and assessed the impact of nonsurgical periodontal therapy on these readings. This study included 20 periodontally healthy persons (H) and 24 patients with chronic periodontitis (P). In every participant, we measured the plaque index, gingival index, probing pocket depth (PD), bleeding on probing, and recession at six sites of every tooth. GCF was collected with Durapore® filter strips from two healthy sites (PD<4 mm; HH) in group H, and from two periodontally diseased sites (PD≥5 mm; PP) and two periodontally healthy sites (PD≤3 mm; PH) in group P. The periodontally diseased participants underwent comprehensive nonsurgical periodontal therapy including deep scaling and root planing under local anesthesia. In these participants, GCF samples were again collected at the same sites 1 and 3 months after therapy. Twelve cytokines (il-1β, il-1ra, il-6, il-8, il-17, b-fgf, g-csf, gm-csf, ifn-γ, mip-1β, vegf, and tnf-α) were assessed using the Bio-Plex suspension array system. Mean plaque index, gingival index, bleeding on probing, PD, and recession were significantly different between groups H and P. Differences between PP and PH sites were not significant for any of the cytokines. Il-1ra, il-6, il-17, b-fgf, gm-csf, mip-1β, and tnf-α differed significantly between HH sites and both PH and PP sites, whereas il-8 was significantly higher only at PP sites. Periodontal treatment increased gm-csf and decreased il-1ra levels in PP sites. Il-1ra, il-6, il-8, il-17, b-fgf, gm-csf, mip-1β, and tnf-α identified patients with chronic periodontitis, rather than diseased sites, suggesting a generalized inflammatory state that is not limited to clinically diseased sites only.
1 INTRODUCTION

Periodontitis is a multifactorial inflammatory disease that destroys the tissues anchoring the teeth in the jaws. The clinical diagnosis is established based on the presence of periodontal pockets and signs for loss of periodontal tissue and bone. However, such assessments reflect the accumulated damage caused by previous episodes, rather than providing information about the current activity of the disease. As periodontitis is thought to be induced by bacteria that activate the host's innate and eventually adaptive immune systems (Kinane, 2001), levels of biomarkers involved in interactions between bacteria and the host defense may reflect the activity of current disease and reveal information on the risk for future disease (Buduneli & Kinane, 2011; Salvi & Lang, 2015). Recent reviews have summarized the function of various molecules in the host's immune response during periodontitis and have suggested that levels of some constituents of saliva or gingival crevicular fluid (GCF) correlate with disease activity or the risk for disease progression (Buduneli & Kinane, 2011; Kinney, Morelli, Oh, et al., 2014; Kinney, Ramseier, & Giannobile, 2007; Preshaw & Taylor, 2011; Ramseier, Kinney, Herr, et al., 2009).